This invention relates to drilling apparatus, and more particularly relates to a novel and improved drilling apparatus with fluid delivery bores for directing fluids from a drill string into drill bits, reaming tools and the like. The invention is adaptable for use with liquids and gaseous materials but is particularly useful in connection with liquids to be used in subsurface formations.
I have previously devised drill bit assemblies as well as reaming devices which are broadly characterized by having a rotary drill bit mounted at the lower end of a conventional drill string and cutter blades pivotally mounted on the drill bit. In high speed earth boring operations to be carried out with fluid assist, the cutter blades are equipped with fluid discharge nozzles which communicate with fluid delivery hoses extending downwardly through the drill string into direct connection with the fluid discharge passages in each of the cutter blades. Although the hoses prevent leakage between the drill string and blades, they are quite bulky, are subject to wear or blow out under repeated use and impose limitations on the ability to mount the cutter blades for free pivotal movement from a vertical to horizontal position at the end of the drill string. Accordingly, there is a need for a fluid delivery system which eliminates the need for fluid delivery hoses and can achieve direct delivery of fluid through bores formed out of the thickness of the blade support body. Still further, and in association with the improved fluid delivery system, is to provide for a novel and improved ball joint between the blade support body and cutter blades which does not interfere with fluid delivery and results in an improved installation, operation, versatility and reliability in use of the blades in downhole operations.
Representative patents are U.S. Pat. No. 2,203,998 to D. J. O'Grady, U.S. Pat. No. 2,814,463 to A. W. Kammerer, Jr., U.S. Pat. No. 3,196,961 to A. W. Kammerer, U.S. Pat. No. 3,552,509 to C. C. Brown, U.S. Pat. No. 3,554,304 to H. D. Link et al, U.S. Pat. No. 3,656,564 to C. C. Brown, U.S. Pat. No. 3,684,041 to A. W. Kammerer et al, U.S. Pat. No. 5,271,472 to R. E. Leturno, U.S. Pat. No. 5,385,205 to C. D. Hailey and U.S. Pat. No. 5,494,121 to A. L. Nackerud.